I have a system with an AMD RX 570, and the various kernel 6.4 releases I've tried all kill video output - it looks like the kernel DRM doesn't see the monitor at all. Even before it gets to X, if I take "rhdb quiet" off the boot line, I get kernel messages up until it tries to switch to the framebuffer mode, I lose video then.

I filed a RHBZ bug against the kernel (since that's where I think the problem is): https://bugzilla.redhat.com/show_bug.cgi?id=2224594

But I haven't gotten any response; I understand kernel devs are busy, not complaining about them, but I was wondering if there might be a better place to go. I can test things, share more logs/info/etc., just need some direction.